Barley

Stem and Leaf Diseases � Fungal

STEM RUST, Puccinia graminis tritici and Puccinia graminis secalis

Symptoms. See description under wheat.
Survival and Spread. See description under wheat.
Other Crops Affected. Rye, wheat.
Control. All currently (1996) available barley varieties are susceptible to race QCC of stem rust. This race was first discovered in North Dakota in 1989. Prior to discovery of this new race, all commonly grown barley varieties were resistant to the prevalent races of stem rust.

LEAF RUST, Puccinia hordei

Symptoms. Small circular orange-brown pustules occur on leaves. Seed test weight and yield may be reduced.
Survival and Spread. Orange spores blow in from the south and spread from plant to plant. Usually, only late planted barley is seriously damaged.
Control. All currently (1996) available varieties are susceptible.
Chemical control. Mancozeb and propiconazole fungicides are registered for barley for leaf rust control.

NET BLOTCH, Pyrenophora teres

Symptoms. Brown blotches on leaves are elongate and soon develop a "netting" pattern. Straw at harvest is dull brown and weak. Small linear brown lesions develop on kernels, with light brown discoloration of the seed.
Survival and Spread. Seed-borne and survives on crop refuse. Spread during the growing season is from airborne spores.
Control. Use crop rotation and sanitation: bury crop residue by tillage before planting. Use seed treatment to control seedling blight. Foliar applications of fungicides registered for barley (see tan spot of wheat) will prevent severe spotting of flag leaf.
Remarks. Associated with cool temperatures; generally more serious in northern North Dakota and on six-row barleys more so than two-row barleys. Often abundant on volunteer barley in a wet, late fall.

POWDERY MILDEW, Erysiphe graminis hordei

See description under wheat.
Other Crops Affected. Wild barley.

SCALD, Rhynchosporium secalis

Symptoms. Water-soaked blue-green blotches appear on the leaves. Later, these turn tan to steel gray, are diamond shaped, and have dark brown borders.
Survival and Spread. Survives on crop refuse. Occasionally seed transmitted. Favored by cool wet weather. Spread by splashing rain.
Control. Use crop rotations. Bury barley stubble and straw before planting barley on barley. The foliar fungicide propiconazole is registered for barley scald control.
Remarks. Most common in northeastern North Dakota near the Canadian border.

SEPTORIA LEAF BLOTCH, Stagonospora avenae f. sp. triticea and Septoria passerinii

Symptoms. Straw-colored, linear blotches develop on leaves; at maturity these blotches contain tiny black fungus fruiting bodies, and leaf sheaths show brownish-gray streaks and blotches. Weakened straw results in lodging. Kernels may be shriveled.
Survival and Spread. Seed-borne and survives on crop residue. Spread during crop season by spores that are rain-splash dispersed.
Other Crops Affected. Wheat and some grasses.
Control. Use crop rotation and seed treatment. Foliar application of fungicides (see leaf rust) can prevent severe infection of the flag leaf.

SPOT BLOTCH, Cochliobolus sativus (= Helminthosporium sativum)

Symptoms. Round to oblong dark brown spots with definite margins develop on leaves; spots merge to form blotches; nodes may turn black as crop matures.
Survival and Spread. Survives as spores and mycelium in soil, on crop refuse, and is seed-borne. Leaf spots come form airborne spores.
Other Crops Affected. Wheat and grasses.
Control. Use crop rotation. Current (1996) two-row barleys are more susceptible than six-row varieties. Foliar fungicides registered for barley may be used to protect the crop against infection.
Remarks. Leaf infections are severe under warm moist conditions.

Stem and Leaf Diseases � Bacterial

BACTERIAL BLIGHT, Xanthomonas translucens pv. translucens Synonym X. campestris pv. translucens

Symptoms. Initial infection occurs on seedlings. On larger leaves, dark green water-soaked stripes become yellowish translucent blotches or stripes, then turn brown. In wet weather, a yellowish exudate develops on lesions. This exudate dries to produce a glistening surface on the leaf. Similar lesions may also develop on kernels.
Survival and Spread. Seed-borne and survives on crop residue. Favored by rainy, damp weather. Spread by splashing rain and insects.
Other Crops Affected. Wild barley species, grasses and wheat.
Control. Use crop rotation and bury crop residue by tillage before planting. Not controlled by foliar fungicides.

Stem and Leaf Diseases � Virus

BARLEY YELLOW DWARF, Barley Yellow Dwarf Virus

Symptoms. Leaf tips turn bright gold or yellow. Later, plants are stunted and whole leaves are bright yellow, occasionally with some purpling discoloration. Affected fields may show uneven and patchy growth.
Survival and Spread. Virus survives in winter grains, primarily in the southern plains. Transmitted by various aphid species -- often introduced with aphid flights from the south.
Other Crops Affected. Oats, wheat, various grasses.
Control. No particular control available. Disease is sporadic in nature, being most severe when virus-carrying aphid populations are high.

Stem and Leaf Diseases � Non-infectious

HEAT CANKER, Non-Infectious

See description under wheat.

PHYSIOLOGICAL LEAF SPOTS, Non-Infectious

Symptoms. Irregular blotches or dark spots of varying size.
Survival and Spread. Non-infectious. Most common when temperatures and humidity are high.
Other Crops Affected. Oats.
Control. Nutrient deficiencies may aggravate spotting.

Head and Seed Diseases � Fungal

BLACK OR SEMI-LOOSE SMUT, Ustilago nigra

Symptoms. Infection occurs during seedling development, but no symptoms show until heading. A black spore mass replaces kernels. Symptoms range from those of loose smut to those of covered smut.
Survival and Spread. Spores spread to healthy seed in the field or during threshing. Spores survive on seed and in soil.
Control. Use seed treatment with a protectant fungicide or carboxin. Semi-loose smut is not detected by the embryo test.

COVERED SMUT, Ustilago hordei

Symptoms. Infection occurs during seedling development, but no symptoms show until heading. In the head, a gray membrane encloses black spore masses that replace the kernels.
Survival and Spread. The spores survive in the smutted heads; membrane breaks at harvest, covering healthy seed with spores. Spores survive on and under hulls cracked during threshing.
Control. Seed treatments with a protectant fungicide or systemic fungicides provide effective control.

BLACK POINT, Cochliobolus sativus (= Helminthosporium sativum) and related fungi

See description under wheat.

ERGOT, Claviceps purpurea

See description under rye.

GLUME BLOTCH, Stagonospora nodorum (synonym Septoria nodorum)

See description under wheat.

LOOSE SMUT, Ustilago nuda

Symptoms. See description under wheat.
Survival and Spread. See description under wheat.
Other Crops Affected. Some grasses but not oats or wheat.
Control. Currently available (1996) varieties are susceptible. Use embryo test and select non-infected seed or treat seed with carboxin-containing fungicide if infection level is greater than 1%.

SCAB (HEAD BLIGHT), Fusarium spp. (Gibberella zeae)

See description under wheat (head blight).

Head and Seed Diseases � Bacterial

BACTERIAL KERNEL BLIGHTS, Pseudomonas syringae pathovars

Symptoms. Dark brown discoloration of the embryo end of the kernel, or well-defined tan to dark brown discolorations on kernel.
Other Crops Affected. Wheat, rye.
Control. Plant disease-free seed. Some cultivars may have more resistance.

BLACK CHAFF, Xanthomonas translucens pv. translucens

See description under wheat.

Root Diseases � Fungal

COMMON ROOT ROT, Cochliobolus sativus(= Helminthosporium sativum)

See description under wheat.
Control. Crop rotation to non-host crop. Use tolerant varieties. A seed treatment product, imazalil, is registered for suppression of common root rot.

TAKE-ALL, Gaeumannomyces graminis tritici

See description under wheat.

Oat

Stem and Leaf Diseases � Fungal

STEM RUST, Puccinia graminis avenae

Symptoms. See description under wheat.
Survival and Spread. See description under wheat.
Other Crops Affected. Confined to oats and wild oats.
Control. Varieties differ significantly in stem rust resistance but those recently released (1996) by North Dakota (Jerry, Paul, NewDak and Valley) are among those with resistance. If possible, plant early. Eradicate common barberry, as the sexual stage occurs on this alternate host, giving rise to new races.

CROWN RUST OR LEAF RUST, Puccinia coronata

Symptoms. Early in the season elongated orange-yellow pustules develop on leaves; later black winter spores form in long raised streaks but do not break through the surface.
Survival and Spread. Black winter spores cause infections of buckthorn in early spring. Later spread is back to oats. Orange summer spores blow in from the south and also form the repeating stage of infections on oats.
Other Crops Affected. Wild oats and grasses.
Control. Oat crown rust races have been shifting or changing rapidly and resistance to the prevalent races has been difficult to maintain. In 1996, only Paul and Milton were designated as resistant to the prevalent races of oat crown rust. Check current variety circulars for descriptions of variety tolerance to crown rust. If possible, plant early. Control wild oats; they serve as a susceptible host in early spring for spores from buckthorn. Eradicate wild buckthorn within a mile of oat fields; the fungus completes the sexual stage on this plant and new races can develop from the sexual process. Mancozeb fungicides (various trade names) and Tilt foliar fungicides are registered for oat and could be used to control crown rust.

Stem and Leaf Diseases � Bacterial

BACTERIAL STRIPE BLIGHT, Pseudomonas striafaciens

Symptoms. First appears as sunken, water soaked dots which later enlarge to water-soaked blotches or stripes that become a rusty brown to black.
Survival and Spread. Survives in crop residue and in seed. Disease develops in seedlings and spreads to other plants by wind and splashing rain. Bacteria enter through stomata (natural pores in leaves), insect punctures, and wounds. Most commonly observed during wet springs in western North Dakota.
Other Crops Affected. Rye.
Control. Crop rotation. Bury crop refuse in spring with tillage. Seed treatment is of doubtful value.
Remarks. Another bacterial disease of oats, halo blight, is rare in North Dakota.

Stem and Leaf Diseases � Virus

OAT RED LEAF, Barley Yellow Dwarf Virus

Symptoms. Affected plants have bronze to reddish discoloration of leaves. Plants are stunted. Yield losses can be severe if infection occurs early in season.
See description under barley. Variety differences in susceptibility to oat red leaf exist. See current variety description circulars for variety susceptibility.

Head and Seed Diseases � Fungal

BLACK LOOSE SMUT, Ustilago avenae

Symptoms. Infection occurs in early stages of germination and seedling development, growing systemically but without symptoms until heading. The grain is replaced by a black powdery mass which breaks apart readily; usually all spikelets on a plant are affected.
Survival and Spread. Spores are on and under the seed hulls.
Other Crops Affected. Grasses and wild oats, but not barley or wheat.
Control. Use carboxin-containing seed treatment products.
Remarks. Not presently common in North Dakota.

COVERED SMUT, Ustilago kolleri

Symptoms. Infection occurs in early stages of germination, growing systemically but without symptoms until heading. Less destruction of the hulls occurs than with loose smut, and the spore mass is blacker and does not break apart as readily as in loose smut.
Survival and Spread. Survives and spreads as spores adhering to surface of seed. Membrane enclosing smut spores breaks during combining.
Other Crops Affected. Grasses and wild oats, but not barley or wheat.
Control. Use fungicidal seed treatment.
Remarks. Not presently common in North Dakota.

SCAB (HEAD BLIGHT), Fusarium spp. (Gibberella zeae)

See description under wheat. Not common in oats.

Head and Seed Diseases � Non-Infectious

BLAST, Physiologic disorder

Symptoms. White empty spikelets (kernels), especially near base of head; reduced yield.
Control. None known.
Remarks. Caused by environmental factors such as drought, soil fertility, heat, etc. Occurs from tillering to pollinating stage.

Rye

Stem and Leaf Diseases � Fungal

STEM RUST, Puccinia graminis secalis

Symptoms. See description under wheat.
Survival and Spread. See description under wheat.
Other Crops Affected. Barley and wild grasses.
Remarks. Rarely serious on rye in North Dakota.

LEAF RUST OR BROWN RUST, Puccinia recondita secalis

Symptoms. See description under wheat.
Survival and Spread. See description under wheat.
Other Crops Affected. Does not attack wheat.
Control. No satisfactory control available.
Remarks. Summer spores must blow in from the south.

TAN SPOT, Pyrenophora tritici-repentis

Symptoms. See description under wheat.
Survival and Spread. See description under wheat.
Control. Crop rotation reduces early-season infection.
Remarks. Usually less severe than on wheat.

Head and Seed Diseases � Fungal

ERGOT, Claviceps purpurea

Symptoms. Large black ergot bodies replace the seed; usually two to five occur per head. In addition, some empty florets (kernels) may occur.
Survival and Spread. Ergot bodies survive on soil from one season to the next. Ergot bodies germinate, producing air-borne spores that infect heads at blossom time. Early infected heads produce spore-laden "honey dew" that is carried to other heads by insects and wind-blown rain.
Other Crops Affected. Durum, grasses, triticale, wheats and barley. Oat is less commonly affected.
Control. Clean seed thoroughly to remove ergot bodies. Use crop rotation with non-cereals; ergot bodies usually survive only one year. Mow or kill grass along fence rows and rock piles before it goes to seed. If a cereal is planted next year, plow under ergot bodies.
Remarks. Ergoty grain is poisonous to livestock and humans. Ergoty hay or pasture grass is poisonous to livestock. Wheat grain with 0.05% ergot is graded "ergoty." Barley is considered ergoty with 0.1% ergot. Small quantities consumed by livestock may result in unstable gait, poor circulation in extremities leading to gangrene and even abortion in pregnant animals.

SCAB (HEAD BLIGHT), Fursarium spp. (Gibberella zeae)

Symptoms. See description under wheat.
Survival and Spread. See description under wheat.
Control. See description under wheat.

Root Diseases � Fungal

COMMON ROOT ROT AND OTHER FUNGI, Helminthosporium sativum and other fungi

Symptoms. See description of root rot and seedling blight under wheat.Fungal Survival and Spread. See description under wheat.Fungal Control. See description under wheat.Fungal Remarks. May occur with Fusarium root rot.

Corn

Leaf Diseases � Fungal

CRAZY TOP, Sclerophthora macrospora

Symptoms. Tassels develop a mass of leafy structures; no pollen is formed. Ears may be replaced by leafy structures. Severely infected plants may have narrow straplike leaves, produce no tassel or ears, be stunted, and develop excessive suckering. Crazy top is rare but may be found in low areas of a field where the soil may be flooded for brief periods shortly after planting.
Survival and Spread. The fungus survives in the soil and in infected crop residue. It is spread in water by swimming spores which are produced when the soil is saturated for at least 48 hours. Infection may occur any time from seed germination until the seedlings are in the four- to five-leaf stage.
Other Crops Affected. Small grains, wild grasses, and sorghum.
Control. No seed treatment is effective and no information is available about hybrid resistance. Provide adequate soil drainage. Control grassy weeds. Avoid planting in low, wet spots.

EYESPOT, Kabatiella zeae

Symptoms. Very small (1/16 to 1/8 inch), translucent circular to oval spots with yellow halos. Initial spots are water-soaked; the spots later develop a brown or purple border, hence called eyespot. Easily seen when leaf held up to light and light transmitted through spots.
Survival and Spread. Overwinters in corn stubble. Spores carried to crop by wind or splashing rain.
Control. Crop rotation and tillage reduce disease levels.

NORTHERN LEAF BLIGHT, Helminthosporium turcicum

Symptoms. Large elliptic water soaked lesions develop on the leaves; these soon turn straw colored to dark brown with a faint target pattern. Lesions form on the husk, but the kernels are not attacked.
Survival and Spread. Fungus survives on crop residue, producing wind-borne spores that infect the new crop.
Other Crops Affected. Sorghums, sudangrass, and Johnsongrass.
Control. Hybrids vary in resistance. Bury corn crop refuse by tillage; use crop rotation.

RUST, Puccinia sorghi

Symptoms. Pustules form on leaves and sometimes on husks. Elongated red pustules bear summer spores; later, black winter spores form in the pustules.
Survival and Spread. Survives on its alternate host, Oxalis sp. (wood sorrel), and as summer spores in the south. Summer spores blow up from the south. Favored by cool temperatures and dew.
Control. Rarely serious enough to require control. Hybrids vary in resistance.

Leaf Diseases � Bacterial

HOLCUS SPOT, Pseudomonas syringae

Symptoms. Elliptic to irregular shaped spots, usually 1/8-3/16 inches in diameter, with a water-soaked or dark green greasy appearance. Later, the spots turn creamy white to tan, resembling parchment paper. On some hybrids a purple border forms around the spots. The spots are usually more numerous on the lower leaves.
Survival and Spread. Survives on crop refuse and various grasses. Favored by warm (77-86°F) weather with wet, windy conditions.
Control. Generally none needed, as this disease has not been shown to be economic. Crop rotation and sanitation (destruction of crop refuse) would reduce overwintering bacteria.
Remarks. Common in North Dakota, especially on sprinkler-irrigated corn.

Leaf Diseases � Virus

MAIZE DWARF MOSAIC, Maize Dwarf Mosaic Virus

Symptoms. A light green mottle or mosaic forms on the upper leaves. Later, fine yellow-green stripes develop and streaks of red may form when nights are cool (below 60°F). The upper portion of the plant may be stunted.
Survival and Spread. Transmitted by aphids and also mechanically by plant contact.
Control. Hybrids may vary in susceptibility.
Remarks. Uncommon in North Dakota. More severe on sweet corn than on field corn. Sporadic appearance depends on virus-carrying aphids migrating from over-wintering areas farther south.

Stalk and Ear Diseases � Fungal

COMMON SMUT, Ustilago maydis

Symptoms. Leaves, stalk, ear, and tassel may be affected and replaced by black spore masses. Spore masses, covered by a persistent grayish membrane, are of varying sizes, but frequently form large "boils."
Survival and Spread. Survives on old crop residue. Spores are airborne. Infections are common in plant injuries caused by cultivation, hail, etc., or during periods unfavorable for good plant growth, such as dry weather and a temperature of 75-93°F or wet and cool weather.
Control. Use crop rotation. Avoid excess nitrogen, especially animal manure. Some hybrids are more resistant than others. Field corn is generally less susceptible than sweet corn. Smut is generally less when plant populations are 12,000-20,000/A. Avoid mechanical damage during cultivation. Seed treatment does not control common smut.

EAR ROT, Fusarium moniliforme, Fusarium graminearum

Symptoms. Individual kernels or groups of kernels are affected, turning pale salmon color to pink and with a tendency to be reddish in later stages. F. moniliforme also produces a stalk rot, similar to Gibberella (see below). Often associated with insect injuries and bird damage.
Survival and Spread. Survives on corn crop residue. Spreads by wind-borne spores and ear-feeding insects. Favored by wet, rainy conditions as crop matures.
Control. Use crop rotation and balanced soil fertility. Hybrids vary in resistance to kernel rot; those with tight husks, which reduce insect damage, show less damage.
Remarks. Ear molds may produce fungal toxins which in turn can be harmful to livestock. Harvested grain with large amounts of ear molds should be tested for mycotoxins prior to feeding.

GIBBERELLA STALK ROT, Gibberella zeae

Symptoms. Stalks are weak; the pith is shredded and pinkish. Lodging frequently occurs. Yield losses occur due to poor filling of ears, early ear drop, early dying of plant or stalk breakage.
Survival and Spread. Fungus overwinters in stalks and stubble; wind-borne spores produce new infections. Stalk rot is promoted by excess soil nitrogen, excessively high plant populations, high rainfall shortly after silking, insect injury, and mechanical damage.
Other Crops Affected. Causes scab (head blight) in wheat, barley, and other small grains.
Control. Crop rotation: do not rotate with barley, corn or wheat. Use balanced soil fertility. Control stalk-boring insects. Hybrids vary in resistance to stalk rot. Harvest early, as soon as crop is mature.
Remarks. Feeding diseased grain or silage may cause feed refusal problems in non-ruminant animals.

DIPLODIA STALK AND EAR ROT, Diplodia maydis

Symptoms. Plants suddenly turn gray-green. Lower stalks are rotted, with disorganized tan or brown pith. A grayish dry rot develops on ears and kernels, progressing upward from the base.
Survival and Spread. Fungus survives on corn crop residue, producing wind-borne spores that affect the new crop. Disease is favored by dry weather followed by 2-3 inches of rainfall several weeks after silking.
Control. Hybrids vary in resistance. Use balanced soil fertility; avoid high nitrogen or low potassium. Avoid high plant populations. Harvest when mature.

HEAD SMUT, Sphacelotheca reiliana

Symptoms. Plants are systemically infected in the seedling stage, may be severely stunted, and may have chlorotic flecks on the leaves. Only the tassels and ears are smutted. All or part of these structures may be filled with black spores covered with a thin membrane. The membrane breaks up easily and quickly exposes the black spores (in contrast to common smut). Thread-like strands occur in the spore masses. Often either the ear or tassel may be partially sterile. Many leaf-like structures may form in the tassel -- this is called phyllody. Yields can be reduced considerably.
Survival and Spread. Spores are soil-borne and survive up to 10 years in the soil. The fungus may be introduced into new areas by wind-borne spores or by spores borne on the surface of the seed. Infection occurs in the seedling stage and is most efficient from soil-borne spores. Buildup is favored by continuous cropping of corn. Spores retain viability after passing through the digestive tracts of cattle or sheep.
Other Crops Affected. Different races attack corn and sorghum (a few sorghum races attack both crops).
Control. Use crop rotation. Plant resistant hybrids. To avoid introducing into new areas, purchase seed treated with carboxin + captan -- this gives almost complete protection against seed-borne infection and partial protection against soil-borne infection.
Remarks. First observed in scattered fields in Minnesota and one in North Dakota in 1980 but has not become a serious problem.